Genetic Risk Scores (GRS) for predicting dementia risk have mostly been used in people of European ancestry with limited testing in other ancestry groups.
We conducted a logistic regression with ...all-cause dementia as the outcome and z-standardised GRS as the exposure across diverse ethnic groups.
There was variation in frequency of APOE alleles across ethnic groups. Per standard deviation (SD) increase in z-GRS including APOE, the odds ratio (OR) for dementia was 1.73 (95%CI 1.69-1.77). Z-GRS excluding APOE also increased dementia risk (OR 1.21 per SD increase, 95% CI 1.18-1.24) and there was no evidence that ethnicity modified this association. Prediction of secondary outcomes was less robust in those not of European ancestry when APOE was excluded from the GRS.
z-GRS derived from studies in people of European ancestry can be used to quantify genetic risk in people from more diverse ancestry groups. Urgent work is needed to include people from diverse ancestries in future genetic risk studies to make this field more inclusive.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background Genetic Risk Scores (GRS) for predicting dementia risk have mostly been used in people of European ancestry with limited testing in other ancestry groups. Methods We conducted a logistic ...regression with all-cause dementia as the outcome and z-standardised GRS as the exposure across diverse ethnic groups. Findings There was variation in frequency of APOE alleles across ethnic groups. Per standard deviation (SD) increase in z-GRS including APOE, the odds ratio (OR) for dementia was 1.73 (95%CI 1.69–1.77). Z-GRS excluding APOE also increased dementia risk (OR 1.21 per SD increase, 95% CI 1.18–1.24) and there was no evidence that ethnicity modified this association. Prediction of secondary outcomes was less robust in those not of European ancestry when APOE was excluded from the GRS. Interpretation z-GRS derived from studies in people of European ancestry can be used to quantify genetic risk in people from more diverse ancestry groups. Urgent work is needed to include people from diverse ancestries in future genetic risk studies to make this field more inclusive.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
there is little research on how people with dementia are involved in treatment decisions at diagnosis.
to measure shared decision making when starting cholinesterase inhibitors, investigate ...associations with contextual factors and explore satisfaction and experience of the diagnostic meeting.
nine UK memory clinics in two geographical locations.
74 people receiving dementia diagnoses (with 69 companions) and 21 doctors.
we video-recorded 74 memory clinic consultations and rated doctor-shared decision making behaviours using the Observing Patient Involvement in Decision Making scale (OPTION-5 scale). Patients and companions rated their satisfaction and experience. Mixed-effects regressions investigated involvement and (i) number people present, meeting length, capacity, cognitive functioning, diagnosis; and (ii) patient/companion satisfaction and consultation experience.
mean consultation time was 26.7 min. Mean OPTION-5 score was 22.5/100 (Standard Deviation = 17.3). Doctors involved patients in decisions more often when patients had mixed dementia (β = 10.13, 95% confidence interval 1.25-19.0, P = 0.025) and in shorter meetings (β = -0.51, 95% CI -0.87 to -0.15, P = 0.006). Patient and companion satisfaction were high and not associated with whether doctors invited patient involvement. Half of patients and one-third companions were uncertain about the meeting outcome, experienced communication barriers and negative emotions.
consultations scored low on shared decision making, but were comparable to other settings and were not lower with more cognitively impaired patients. Negative patient and companion experiences reflect the importance of supporting healthcare providers to address patient and companion emotions and need for information.
Schizophrenia is a highly heritable, neuropsychiatric disorder characterized by episodic psychosis and altered cognitive function. Despite success in identifying genetic variants associated with ...schizophrenia, there remains uncertainty about the causal genes involved in disease pathogenesis and how their function is regulated.
We performed a multi-stage epigenome-wide association study, quantifying genome-wide patterns of DNA methylation in a total of 1714 individuals from three independent sample cohorts. We have identified multiple differentially methylated positions and regions consistently associated with schizophrenia across the three cohorts; these effects are independent of important confounders such as smoking. We also show that epigenetic variation at multiple loci across the genome contributes to the polygenic nature of schizophrenia. Finally, we show how DNA methylation quantitative trait loci in combination with Bayesian co-localization analyses can be used to annotate extended genomic regions nominated by studies of schizophrenia, and to identify potential regulatory variation causally involved in disease.
This study represents the first systematic integrated analysis of genetic and epigenetic variation in schizophrenia, introducing a methodological approach that can be used to inform epigenome-wide association study analyses of other complex traits and diseases. We demonstrate the utility of using a polygenic risk score to identify molecular variation associated with etiological variation, and of using DNA methylation quantitative trait loci to refine the functional and regulatory variation associated with schizophrenia risk variants. Finally, we present strong evidence for the co-localization of genetic associations for schizophrenia and differential DNA methylation.
Dementia diagnostic criteria in Down syndrome Sheehan, Rory; Sinai, Amanda; Bass, Nick ...
International journal of geriatric psychiatry,
August 2015, Letnik:
30, Številka:
8
Journal Article
The study of biological age acceleration may help identify at-risk individuals and reduce the rising global burden of age-related diseases. Using DNA methylation (DNAm) clocks, we investigated ...biological aging in schizophrenia (SCZ), a mental illness that is associated with an increased prevalence of age-related disabilities and morbidities. In a whole blood DNAm sample of 1090 SCZ cases and 1206 controls across four European cohorts, we performed a meta-analysis of differential aging using three DNAm clocks (i.e., Hannum, Horvath, and Levine). To dissect how DNAm aging contributes to SCZ, we integrated information on duration of illness and SCZ polygenic risk, as well as stratified our analyses by chronological age and biological sex.
We found that blood-based DNAm aging is significantly altered in SCZ independent from duration of the illness since onset. We observed sex-specific and nonlinear age effects that differed between clocks and point to possible distinct age windows of altered aging in SCZ. Most notably, intrinsic cellular age (Horvath clock) is decelerated in SCZ cases in young adulthood, while phenotypic age (Levine clock) is accelerated in later adulthood compared to controls. Accelerated phenotypic aging was most pronounced in women with SCZ carrying a high polygenic burden with an age acceleration of + 3.82 years (CI 2.02-5.61, P = 1.1E-03). Phenotypic aging and SCZ polygenic risk contributed additively to the illness and together explained up to 14.38% of the variance in disease status.
Our study contributes to the growing body of evidence of altered DNAm aging in SCZ and points to intrinsic age deceleration in younger adulthood and phenotypic age acceleration in later adulthood in SCZ. Since increased phenotypic age is associated with increased risk of all-cause mortality, our findings indicate that specific and identifiable patient groups are at increased mortality risk as measured by the Levine clock. Our study did not find that DNAm aging could be explained by the duration of illness of patients, but we did observe age- and sex-specific effects that warrant further investigation. Finally, our results show that combining genetic and epigenetic predictors can improve predictions of disease outcomes and may help with disease management in schizophrenia.
Objective:
Lithium remains a first-line treatment for bipolar disorder, but the mechanisms by which it prevents the recurrence of mood episodes are not known. The authors utilized data from a ...genomewide association study to examine associations between single nucleotide polymorphisms (SNPs) and the outcome of lithium treatment in two cohorts of patients with bipolar I disorder or bipolar II disorder.
Method:
The hazard for mood episode recurrence was examined among 1,177 patients with bipolar I disorder or bipolar II disorder, including 458 individuals treated with lithium carbonate or citrate, who were participants in the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD) cohort. SNPs showing the greatest evidence of association in Cox regression models were then examined for association with positive lithium response among 359 bipolar I or II disorder patients treated with lithium carbonate or citrate in a second cohort from the University College London.
Results:
The strongest association in the STEP-BD cohort (minimum p=5.5×10
-7
) was identified for a region on chromosome 10p15 (rs10795189). Of the regions showing suggestive evidence (p<5× 10
-4
) of association with lithium response, five were further associated with positive lithium response in the University College London cohort, including SNPs in a region on chromosome 4q32 spanning a gene coding for the glutamate alpha-amino-3-hydroxy-5-methyl-4-isoxazolpropionate (AMPA) receptor
GRIA2
.
Conclusions:
Multiple novel loci merit further examination for association with lithium response in bipolar disorder patients, including one region that spans the
GRIA2
gene, for which expression has been shown to be regulated by lithium treatment.
Increased rates of visual impairment are observed in people with schizophrenia.
We assessed whether genetically predicted poor distance acuity is causally associated with schizophrenia, and whether ...genetically predicted schizophrenia is causally associated with poorer visual acuity.
We used bidirectional, two-sample Mendelian randomisation to assess the effect of poor distance acuity on schizophrenia risk, poorer visual acuity on schizophrenia risk and schizophrenia on visual acuity, in European and East Asian ancestry samples ranging from approximately 14 000 to 500 000 participants. Genetic instrumental variables were obtained from the largest available summary statistics: for schizophrenia, from the Psychiatric Genomics Consortium; for visual acuity, from the UK Biobank; and for poor distance acuity, from a meta-analysis of case-control samples. We used the inverse variance-weighted method and sensitivity analyses to test validity of results.
We found little evidence that poor distance acuity was causally associated with schizophrenia (odds ratio 1.00, 95% CI 0.91-1.10). Genetically predicted schizophrenia was associated with poorer visual acuity (mean difference in logMAR score: 0.024, 95% CI 0.014-0.033) in European ancestry samples, with a similar but less precise effect that in smaller East Asian ancestry samples (mean difference: 0.186, 95% CI -0.008 to 0.379).
Genetic evidence supports schizophrenia being a causal risk factor for poorer visual acuity, but not the converse. This highlights the importance of visual care for people with psychosis and refutes previous hypotheses that visual impairment is a potential target for prevention of schizophrenia.
Genome-wide association studies have reported a genetic overlap between borderline personality disorder (BPD) and schizophrenia (SCZ). Epidemiologically, the direction and causality of the ...association between thyroid function and risk of BPD and SCZ are unclear. We aim to test whether genetically predicted variations in TSH and FT4 levels or hypothyroidism are associated with the risk of BPD and SCZ.
We employed Mendelian Randomisation (MR) analyses using genetic instruments associated with TSH and FT4 levels as well as hypothyroidism to examine the effects of genetically predicted thyroid function on BPD and SCZ risk. Bidirectional MR analyses were employed to investigate a potential reverse causal association.
Genetically predicted higher FT4 was not associated with the risk of BPD (OR: 1.18; P = 0.60, IVW) or the risk of SCZ (OR: 0.93; P = 0.19, IVW). Genetically predicted higher TSH was not associated with the risk of BPD (OR: 1.11; P = 0.51, IVW) or SCZ (OR: 0.98, P = 0.55, IVW). Genetically predicted hypothyroidism was not associated with BPD or SCZ. We found no evidence for a reverse causal effect between BPD or SCZ on thyroid function.
We report evidence for a null association between genetically predicted FT4, TSH or hypothyroidism with BPD or SCZ risk. There was no evidence for reverse causality.
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